A Growing Stream of Illegal Immigrants Choose to Remain Despite the Risks

More Mexican immigrants are in the United States illegally — without the proper authorization to reside or work here — than ever before.

The newest arrivals from Mexico are putting down roots for longer periods and settling in states that have rarely encountered Latin American immigrants, places like North Carolina, Tennessee, Georgia and Minnesota. These new immigrants are also bringing young families with them, a trend that has strained some schools and other public services.

An estimated 6.2 million illegal immigrants from Mexico now live in the United States, about half the total number of all Mexicans residing here, according to data compiled by the Pew Hispanic Center, a research group in Washington. In all, more than 10 percent of Mexico’s 116 million citizens now live in the United States as legal or illegal immigrants.

Mexicans have been migrating to the United States for more than a century, but until recently most did so legally. The heavy stream of illegal immigration did not begin until the 1970s. In 1970, the United States was home to 750,000 Mexicans, primarily legal immigrants, census figures show.

The late 1990s saw a spike in the population of illegal workers entering the country, drawn by the boom in the economy, particularly in the service and construction industries. Of the Mexican immigrants now living here, 85 percent arrived here without authorization, the Pew center estimates.

Ask Mexican immigrants why they risk coming to the United States illegally, and the reasons seldom vary: better wages, plentiful jobs, family ties and future opportunity.

“It’s the same things you and I want for our families,” said Demetrios Papademetriou, president of the Migration Policy Institute, a nonpartisan research group in Washington.

For most Mexicans, obtaining a visa to live here is next to impossible because either there are too few visas available or the wait is too long. It is also increasingly difficult for Mexicans, particularly poor Mexicans, to obtain tourist visas since the American government tries to screen out people who are likely to remain here illegally.

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Immigrants who get caught living in the United States without authorization typically face deportation and are barred from re-entering the country legally for as long as 10 years. For most Mexicans, that prohibition does not dissuade them from returning but means daunting complications of time and money. Often they must pay a smuggler to help them cross back into the United States at a cost of thousands of dollars, which can take years to save or pay back.

Moreover, immigrants who have been deported once and are caught again can face prosecution and a prison sentence. In recent years, the United States government has been stricter in pursuing these cases to send a message to other illegal immigrants.

Increased enforcement along the border in recent years — especially since the Sept. 11 attacks — appears to have deterred few immigrants, Mr. Papademetriou said, but has resulted in a greater demand for smugglers, higher prices for smuggling and more deaths from crossing the border. It has also discouraged people from going back home.

A number of Mexicans also enter the United States with border-crossing cards and then remain here, although it is impossible to know how many. The card allows Mexicans to visit for short periods, between 72 hours and 30 days, and they must stay within 25 miles of the border. People often use these cards to make quick shopping trips. More than 732,000 of the cards were issued last year.

Today’s new wave of illegal immigrants, many of them with children in tow, has rippled through the nation’s schools. Communities where immigrants gather face challenges to educate children speaking only Spanish whose parents often had limited schooling at home.

Because they fill low-wage jobs with no or few benefits, Mexicans also suffer a high poverty rate. In some labor markets, they compete for jobs with the nation’s most disadvantaged, especially young blacks without high school diplomas, scholars at the Center for Labor Market Studies at Northeastern University found.

A version of this article appears in print on , on Page A26 of the New York edition with the headline: A Growing Stream of Illegal Immigrants Choose to Remain Despite the Risks. Order Reprints|Today's Paper|Subscribe